opening on the platform. The openings are entirely lined with white glazed tiles, and the outward ends open into an area, the back of which is inclined at an angle of 45°, and the whole also lined with white glazed tiles, and covered with glass, except where some iron gratings are provided for ventilation. The tiles reflect the daylight so powerfully that but little gas is required for the illumination of the station in the day-time. The arched roofs of these stations are supported by piers of brickwork, 10 ft. apart, 5 ft. 6 in. deep, and 3 ft. 9 in. wide. In the spaces between the piers vertical arches, like parts of the brick lining of a well, are wedged in, to resist the thrust of the earth, and a straight wall is built inside of this between the piers, to form the platform wall of the station. The tops of the piers are connected by arches, and are thus made to bear the weight of the arched roof, which has 2 ft. 3 in. thickness of brickwork at the crown, and a much greater thickness towards the haunches. [Illustration: FIG. 50.—_Gower Street Station, Metropolitan Railway._ ] The benefit derived by the public from the completion of the Metropolitan Railway was greatly increased by the subsequent construction of another railway—“The Metropolitan District,” which, joining the Metropolitan at Paddington, makes a circuit about the west-end of Hyde Park, and passing close to the Victoria Terminus of the London, Chatham, and Dover and the Brighton and South Coast Railways, reaches Westminster Bridge, and then follows the Thames Embankment to Blackfriars Bridge, where it leaves the bank of the river for the Mansion House, Mark Lane and Aldgate stations. This line, taken in conjunction with the Metropolitan, forms the “_inner circle_” of the railway communication in London. The circuit was for a long time incomplete at the east by the want of connection between the Mansion House Station and that of Moorgate Street, although these stations are but little more than half a mile apart. A line connecting these two points has lately been constructed at great cost, and the public now possess a complete circle of communication. The number of trains each day entering and leaving some of the stations on the Metropolitan system is very great. Moorgate Street Station—a terminus into which several companies run—may have about 800 trains arriving or departing in the course of a day. _THE PACIFIC RAILWAY._